c - 具有单个成员的结构是否具有与成员类型相同的性能？

Question

具有单个成员的 struct 是否具有与成员类型相同的性能(内存使用和速度)？

示例:

这段代码是一个只有一个成员的struct:

struct my_int
{
    int value;
};

my_int的性能和int一样吗？

Answer 1

同意@harper总体而言，但要注意以下几点:

“非结构化”数组和结构化数组之间存在典型差异。

char s1[1000];
// vs
typedef struct {
  char s2[1000];
} s_T;
s_T s3;

调用函数时...

void f1(char s[1000]);
void f2(s_T s);
void f3(s_T *s);

// Significant performance difference is not expected.
// In both, only an address is passed.
f1(s1);
f1(s3.s2);

// Significant performance difference is expected.
// In the second case, a copy of the entire structure is passed.
// This style of parameter passing is usually frowned upon.
f1(s1);
f2(s3);

// Significant performance difference is not expected.
// In both, only an address is passed.
f1(s1);
f3(&s3);